LAX08LA198

NTSB accident investigation · Eurocopter AS 350 B3 · Ash Fork, AZ · June 27, 2008

Accident · Serious injuriesLimited investigationFinal report
Date
June 27, 2008, 03:41 local (10:41 UTC)
Place
Ash Fork, AZ
Injuries
3 serious
Damage
Substantial damage
Phase of flight
Approach
Aircraft
N586AEEurocopter AS 350 B3
Defining event
Approach: Loss of visual reference
Weather
Visual (VMC) · Night
Status
Completed · report June 11, 2009
Report
Approved by Office Director
Parties
Federal Aviation Administration FSDO
Case key
68331

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

The pilot's spatial disorientation resulting in his failure to detect and compensate for an unintentional descent during a go-around. Contributing to the accident were the pilot's inadequate choice of landing approach, reduced visibility from brownout conditions, and the dark night.

Findings · 6

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Performance/control parameters: climb rateAircraft › Aircraft oper/perf/capability · Not attained/maintainedEurocopter AS 350 B3: 1 caseAll aircraft: 265 casesProbable cause
Ceiling/visibility/precip: sand/dust stormEnvironmental issues › Conditions/weather/phenomena · Effect on operationEurocopter AS 350 B3: 1 caseAll aircraft: 1 caseProbable cause
Light condition: darkEnvironmental issues › Conditions/weather/phenomena · Effect on operationEurocopter AS 350 B3: 2 casesAll aircraft: 448 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

The helicopter pilot was dispatched to a highway motorcycle accident on the night flight. The pilot reported that he was wearing night vision goggles and that the weather en route was clear skies with unrestricted visibility. As he approached the vehicle accident location he contacted the incident commander by radio and was instructed to land at a landing zone (LZ) about 1.5 miles north of the vehicle accident location. The pilot performed an orbit around the vehicle accident site and determined that it would be safe for him to land there directly. He once again contacted the incident commander and requested to land but the incident commander instructed the pilot to continue north to the LZ. Upon arrival at the LZ, the pilot reconnoitered the site and observed that the incident commanders' vehicle was situated in a location that would make the approach for landing steeper than normal. He therefore elected to change the approach to a route that would take him over a sparsely vegetated dirt field, followed by a gravel road, and then a paved road for the final approach to touchdown. Halfway through the approach the flight encountered brownout conditions and he began to perform a go-around. He reported being confident that he had initiated a climb, but shortly thereafter the helicopter impacted the ground. During the impact sequence the helicopter rolled on its right, and the main rotor, tail rotor, and engine separated from the fuselage. The pilot stated that the helicopter and engine had no mechanical failures or malfunctions during the flight.

Factual narrative

HISTORY OF FLIGHT On June 27, 2008, at 0341 mountain standard time, a Eurocopter AS 350 B3, N586AE, collided with level terrain during an attempted go-around near Ash Fork, Arizona. Petroleum Helicopters, Inc. (PHI), was operating the helicopter under the provisions of 14 Code of Federal Regulations Part 91. The certificated airline transport pilot and two medical crew members sustained serious injuries; the helicopter sustained substantial damage. The flight originated from Ernest A. Love Field Airport (PRC), Prescott, Arizona, and was en route to a traffic accident. Night visual meteorological conditions prevailed and a company flight plan was filed. The pilot and operator provided written statements to the National Transportation Safety Board investigator-in-charge (IIC). The pilot stated that his duty shift began at 1830 on June 26. He reported that shortly after beginning his shift he completed his normal duties, which included performing a preflight check on the accident helicopter, and checking the current and forecast area weather. At 0310 on the day of the accident, the pilot received a dispatch notification informing him that a motorcycle accident had occurred on US Highway 89, south of Ash Fork. Five minutes later he was cleared to launch to the accident, and at 0320, he departed in the helicopter with a medical crew that included a nurse and a paramedic. The pilot reported that for the 20-minute flight he was wearing his Night Vision Goggles, and that the weather en route was clear skies with unrestricted visibility. He stated that he had an, "average to good night vision picture." As the pilot passed the town of Chino, Arizona, he observed the emergency vehicles' lights to the north. The pilot radio contacted the incident commander, and was informed that he was to land about 1.5 miles north of the accident site. The pilot performed an orbit around the accident site and determined that it would be safe for him to land there directly. He once again contacted the incident commander, and requested to land at the accident site. The incident commander instructed the pilot to continue north to the LZ. The pilot then proceeded to fly the helicopter to the LZ, which was on a road adjoining highway 89. He flew over the LZ and observed that the placement of the incident commander's vehicle would cause him to make an approach that he determined was steeper than normal. He elected to approach the landing zone from the west. This route of flight took him over a sparsely vegetated dirt field, followed by a gravel road, and then a paved road. The pilot reported beginning the approach portion of the flight about 300 feet laterally from the LZ at an altitude of between 150 and 200 feet agl. He stated that halfway through the approach he was surprised by the amount of dust being created by the rotor wash, and he commented to the flight crew, "I don't like this very much." He then observed dust rising about halfway up his windshield, and he initiated ago-around. He reported increasing the collective and referencing the attitude indicator to maintain a level and, "slightly" nose low attitude. He expressed concern that the dust was now filling about 3/4 of the windshield, but he reported being confident that he had initiated a climb. Shortly thereafter, the helicopter impacted the ground. During the impact sequence the helicopter rolled on its right, and the main rotor, tail rotor, and engine separated from the fuselage. The pilot stated that the helicopter and engine had no mechanical failures or malfunctions during the flight. PERSONNEL INFORMATION The pilot, age 61, held an airline transport pilot certificate with ratings for airplane multiengine land and helicopter. In addition, he held commercial privileges for airplane single engine land and sea, and instrument helicopter. The pilot held a second-class medical certificate issued in February 2008, with the limitation that he must wear corrective lenses. The pilot reported that he had a total flight time of 9,636 hours. He logged 25 hours in the accident helicopter make and model over the last 90 days, and 7 hours in the last 30 days, which included 5 hours under night conditions. He reported 136 total flight hours in this make and model, and 3,636 total flight hours in helicopters. Records from the operator revealed that at the time of the accident the pilot had met the currency requirements outlined in the Federal Aviation Administration (FAA) approved PHI Helicopter Night Vision Goggle Operations Specifications (HNVGO). In a telephone interview with the Safety Board IIC, the pilot reported that he had amassed about 500 hours of total flight experience using Night Vision Goggles during service as a helicopter pilot in the Army National Guard. He further stated that he began employment with PHI in February 2007, and that this was his first position as a pilot in Emergency Medical Services. AIRCRAFT INFORMATION The helicopter was a Eurocopter AS 350 B3, serial number 3725, manufactured in 2003. The helicopter was powered by Turbomeca Arriel 2B engine, serial number 22408. The operator maintained the helicopter in accordance with an FAA approved aircraft inspection program (AAIP). The operator reported that the helicopter had a total airframe time of 1,521 hours at the last AAIP Inspection, which occurred 35 flight hours prior to the accident. The helicopter was not certified for instrument flight rules (IFR). The helicopter was equipped with a radar altimeter. METEOROLOGICAL INFORMATION The closest aviation weather observation station was located at PRC, which was 38 miles south of the accident site. The elevation of the weather observation station was 5,045 feet mean sea level (msl). An aviation routine weather report (METAR) for PRC was issued at 0353 MST. It stated: winds from 170 degrees at 7 knots; visibility 10 miles; skies clear; temperature 16 degrees Celsius; dew point 5 degrees Celsius; altimeter 30.10 inches of mercury.

Aircraft

Registration
N586AE
Reported as
Eurocopter AS 350 B3
Category
Helicopter
Serial number
3725
Airframe hours
1,521
Engine
Turbomeca Arriel 2B, 847 lbs thrust, turbo shaft
Damage
Substantial damage
Flight
Positioning · Part 91
Operator
PHI Incorporated
Registered owner
PHI Incorporated
Airworthiness certificate
Standard, Normal
Departed
PRC · Prescott, AZ
Destination
Ash Fork, AZ
Flight plan
Company VFR

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
61
Injuries
Serious
Certificate
Airline transport
Airplane ratings
Multi-engine land, Single-engine sea, Single-engine land
Instrument ratings
Airplane, Helicopter
Medical
Class 2, With waivers/limitations
Last flight review
January 15, 2008
Seat
Right
Flight hours
9,636 total · 136 in this make and model · 6,875 as pilot in command · 25 in the last 90 days · 7 in the last 30 days

Weather

Conditions
Visual (VMC) · Night
Wind
170° at 7 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
61 °F, dew point 41 °F
Altimeter
30.10 inHg
Observed at
PRC, 38 nm away